Device for assisted movement of a disabled leg

ABSTRACT

The present invention is a device for controlled assisted movement of a disabled and/or injured leg. The device includes a dynamic elastic force member that extends longitudinally between a proximal end and a distal end of the dynamic elastic force member. The device further includes a handle operably coupled to the proximal end of the dynamic elastic force member and a suspension apparatus operably coupled to the proximal end of the dynamic elastic force member. Further, the device includes an attachment apparatus operably coupled to the distal end of the dynamic elastic force member. The device exerts a motive force that assists in movement of the leg when the user pulls the handle.

FIELD OF THE INVENTION

The present invention relates generally to the field of kinesitherapy for exercising a joint or limb, more particularly, the present invention provides for controlled assisted movement of a disabled leg after injury or surgery and to facilitate the recovery of a natural range of motion.

BACKGROUND OF THE INVENTION

An injury to the knee such as a rupture of the quadriceps (thigh) muscle that separates it from the patella (kneecap) leaves the leg without effective control for simple activity. Even after the application of a knee splint that holds the knee completely straight, there is a need for the injured person to be able to control their own limb while moving about, particularly when attempting to lift the injured leg against the force of gravity. Such control of a limb is required for simple activities like lifting the leg into a car or anytime limbs are mobilized postoperatively.

Crutches and a knee splint are typically provided after a knee injury, but leg control is still a problem. Even when a knee splint is worn, the muscle will contract when lifting the leg and re-injury is a significant risk during simple activities such as getting into bed or into a car.

Surgical repair requires many weeks of healing before the strength of the repair of a muscle or tendon can withstand the active muscle force of the quadriceps muscle to control the leg against gravity. After knee surgery, the pain associated with movement often causes patients to keep the joint immobile. This immobility may result in the tissue around the joint becoming stiff and scar tissue formation resulting in a joint that has a limited range of motion. Once the joint stiffens and scar tissue forms, it can take months of physical therapy to recover that motion.

One method for assisting in recovering full motion of a disabled leg is a Continuous Passive Motion (CPM) machine. CPM is a postoperative treatment method that assists recovery after joint surgery by gently bending (flexing) and straightening (extending) the knee. CPM may also reduce the number of post-operative blood clots and prevent scar tissue from forming. CPM machines are sometimes used in knee rehabilitation. However, the CPM machines have several disadvantages. They are cumbersome and confine the patient to the machine. Further, the CPM machines are expensive to rent or purchase.

Several devices exist to assist a user in moving or exercising limbs. One such device is disclosed in U.S. Pat. No. 3,739,772 to Ennis (“'772 patent”). The '772 patent discloses a shoulder strap harness for use with a walking cast. The shoulder strap harness facilitates leg movement and fatigue by transferring the weight of the leg and walking cast to the user's shoulder. The shoulder harness, however, imparts weight and force onto the shoulder, which can strain and fatigue the shoulder and surrounding anatomy. The '772 patent does not disclose a mechanism, such as a handle, to enable the user to manually manipulate the device and thus administer motive force to the limb.

Another device is disclosed in U.S. Pat. No. 6,004,282 to Whitley (“'282 patent”). The '282 patent discloses an apparatus for lifting an injured leg which includes a flexible pull line. The flexible pull line allows the user to manually maneuver the leg. However, the pull line is located about the user's knee such that the user must bend over to grab the line. Further, the '282 patent does not disclose a mechanism to protect the quadriceps muscle.

A strap device is disclosed in U.S. Pat. No. 4,252,112 to Joyce to assist the user in moving a fully or partially paralyzed leg (“'112 patent”). The strap system of the '112 patent acts as a brace for the leg and allows the user to hike up their hip while keeping the leg straight. The strap and pulley system ensures the knee does not buckle when the user places weight on their fully or partially paralyzed leg. The device disclosed in the '112 patent ensures the user's leg remains straight, however, it does not assist the user in administering motive force on the limb to facilitate the natural range of motion.

U.S. Pat. No. 4,599,996 discloses a device for manipulating a leg (“'996 patent”). The '996 patent discloses a device having a rigid lifter member actuated by a lever that is pivotally connected to a base member. There is no elastic force disclosed in the '996 patent. Further, the device disclosed in the '996 patent is cumbersome and bulky such that it would be difficult at best for a user to easily maneuver around while wearing the device.

While there are existing devices to assist movement of a disabled leg or to assist in rehabilitating a disabled leg, it would be desirable to provide a system that overcomes the limitations of these existing devices, yet is simple, inexpensive and easy to use.

SUMMARY OF THE INVENTION

The present invention is a simple, inexpensive mechanism to assist in the rehabilitation of knee or leg injuries and provide the patient with a controlled assisted means of moving a disabled and/or injured leg. The present invention utilizes a dynamic elastic force member to facilitate injury rehabilitation by complementing a supervised physical therapy program and administering a motive force to the disabled and/or injured leg for the patient's exercise program while at home.

The present invention incorporates a dynamic elastic force member, with a handle, a proximal attachment on or about the user's waist and a distal attachment on or about the user's foot or footwear. The present invention is particularly useful for lifting the leg into bed or onto a foot rest when sitting (also saving a helper's back), placing the foot into the car, controlling the leg while walking on stairs with “toe-touch” weight bearing on crutches. Without this device more attendant care of medical personnel, friend or spouse is required for these activities to diminish pain and/or avoid re-injury of the surgically repaired limb.

The present invention administers motive force and greatly facilitates knee control during active or gravity driven knee flexion and provides passive extension with the quadriceps relaxed during early healing after surgical repair of the quadriceps muscle. A patient may use the present invention following suture removal for assisted active knee extension exercise to help rehabilitate the knee without excessively loading the healing quadriceps muscle. Early knee motion is permitted because the present invention provides extension force to help straighten the knee without activating the quadriceps muscle. As a result, the range of motion is more rapidly restored without damaging the repair. At four to six weeks after surgery, the present invention may be used to assist progressively increasing use of the quadriceps while maintaining safe control of the leg.

The present invention is significantly less expensive than renting or buying a CPM machine for post-operative total knee arthroplasty (TKA) knee rehabilitation or following revision TKA that has a poor patellar tendon or has required partial release or lengthening of the quadriceps mechanism. The present invention could complement a CPM used in the hospital when the patient was ready to go home and would answer the need for protected motion of the knee for several weeks.

It is one object of the present invention to provide a low cost, easy to use, knee rehabilitation device.

It is another object of the present invention to provide a low cost, easy to use, device that administers motive force to an injured and/or disabled extremity.

It is yet another object of the present invention to provide a device to assist users in their three point gait when using crutches.

It is still another object of the present invention to provide a device for protected motion of an injured knee.

It is an object of the present invention to assist the user with knee extension and leg rehabilitation exercises.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the present invention.

FIG. 2 depicts the device of the present invention in use.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1 the device 10 includes a handle 20 on its proximal end. The handle 20 may be configured to allow the user direct handheld manipulation of the device 10 to administer motive force to the user's leg at will without risk of re-injury or pain. The device 10 may be attached on or about the user's foot or footwear via the distal attachment apparatus 50. A dynamic elastic force mechanism 40 extends longitudinally between the handle 20 and the distal attachment apparatus 50.

Handle 20 may be a strap configured in a loop and constructed of fabric or other suitable material. In another embodiment, the handle 20 may be a loop formed integrally into the dynamic elastic force means. Alternatively, handle 20 may be a simple handgrip constructed of a semi-rigid molded plastic or any other suitable material. As shown in FIG. 2, the handle 20 is placed conveniently at or about the user's waist. This handle 20 placement provides the user with the ability to administer motive force to the disabled and/or injured leg without bending over and risking injury to the user's back.

The handle 20 and dynamic elastic force mechanism 40 are configured to provide controlled assisted flexion and extension to protect repair of the quadriceps or other musculature, tendons and/or ligaments. As shown in FIG. 2, the user may grip the handle 20 thus engaging the elastic force mechanism 40 such that a motive force is administered to the disabled and/or injured leg.

The dynamic elastic force mechanism 40 may be constructed of a bungee cord-like material, surgical rubber tubing, neoprene cording or any such material that provides a dynamic elastic force. The dynamic elastic force mechanism 40 may be color coded for length, elastic strength, size or other dimensional attributes. The dynamic elastic force mechanism 40 may be attached to the handle 20 and the distal attachment apparatus 50 via fasteners.

The device 10 may further include a proximal suspension mechanism 30. The proximal suspension mechanism 30 is configured to suspend the leg control device at or about the user's waist, belt, belt loop, pocket or other suitable area. The proximal suspension apparatus may be in the form of a belt, strap, elastic cording, clip, fastener or any other mechanism suitable for suspending the device at or about the user's waist. The proximal suspension mechanism 30 may include Velcro®, snaps or other mechanisms to adjustably place the proximal suspension mechanism on or about a user's waist. The proximal suspension mechanism 30 allows the user to suspend the device 10 from their person, thereby freeing both hands when the device is not in use, but keeping it easily accessible. Further, placement of the handle and the proximal suspension mechanism at or about the user's waist lessens the risk of the user losing their balance and falling as may happen if the user is required to bend over and maneuver their leg.

The distal attachment apparatus 50 may be placed on or about the user's foot or footwear. The distal attachment apparatus 50 may be in the form of a simple loop integrally formed into the dynamic elastic force mechanism. The distal attachment apparatus 50 may be a clip or fastener used to affix the device to footwear or shoelaces. In another embodiment, the distal attachment apparatus 50 may be a strap or cording looped or wrapped around the user's foot or footwear. The distal attachment apparatus 50 may include Velcro®, snaps or other mechanisms to adjustably place the distal attachment apparatus on or about a user's foot or footwear. 

1. A device for controlled assisted movement of a disabled leg of a user comprising: a dynamic elastic force member extending longitudinally between a proximal end and a distal end of the dynamic elastic force member; a handle operably coupled to the proximal end of the dynamic elastic force member; suspension means operably coupled to the proximal end of the dynamic elastic force member for suspending the proximal end of the dynamic elastic force member generally at the waist of the user; and attachment means operably coupled to the distal end of the dynamic elastic force member for attaching the distal end of the dynamic elastic force member generally to the foot of the user; whereby the device exerts a motive force that assists in movement of the leg when the handle is pulled by the user.
 2. The device of claim 1, wherein the suspension means is a strap.
 3. The device of claim 1, wherein the suspension means is a fastener.
 4. The device of claim 1, wherein the attachment means is a strap.
 5. The device of claim 1, wherein the attachment means is a fastener.
 6. The device of claim 1, wherein the handle is integrally formed into the dynamic elastic force member.
 7. A device for controlled assisted movement of a disabled leg of a user comprising: a dynamic elastic force member extending longitudinally between a proximal end and a distal end of the dynamic elastic force member; a handle operably coupled to the proximal end of the dynamic elastic force member; a suspension apparatus operably coupled to the proximal end of the dynamic elastic force member; and an attachment apparatus operably coupled to the distal end of the dynamic elastic force member, whereby the device exerts a motive force that assists in movement of the leg when the handle is pulled by the user. 